droop vs lean

droop

verb
  • To hang downward; to sag. 

  • To lose all energy, enthusiasm or happiness; to flag. 

  • To slowly become limp; to bend gradually. 

  • To proceed downward, or toward a close; to decline. 

  • To allow to droop or sink. 

noun
  • A condition or posture of drooping. 

  • A hinged portion of the leading edge of an aeroplane's wing, which swivels downward to increase lift during takeoff and landing. 

  • Something which is limp or sagging. 

lean

verb
  • To hang outwards. 

  • To incline, deviate, or bend, from a vertical position; to be in a position thus inclining or deviating. 

  • To conceal. 

  • Followed by against, on, or upon: to rest or rely, for support, comfort, etc. 

  • To press against. 

  • To thin out (a fuel-air mixture): to reduce the fuel flow into the mixture so that there is more air or oxygen. 

  • To incline in opinion or desire; to conform in conduct; often with to, toward, etc. 

noun
  • An inclination away from the vertical. 

  • An organism that is lean in stature. 

  • Meat with no fat on it. 

  • A recreational drug based on codeine-laced promethazine cough syrup, especially popular in the hip hop community in the southeastern United States. 

adj
  • Having little fat. 

  • Having little extra or little to spare; scanty; meagre. 

  • Having a low proportion or concentration of a desired substance or ingredient. 

  • Slim; not fleshy. 

  • Efficient, economic, frugal, agile, slimmed-down; pertaining to the modern industrial principles of "lean manufacturing". 

How often have the words droop and lean occurred in a corpus of books? (source: Google Ngram Viewer )